System for selecting one of several receivers connected to a common conductor.



i w L NO. 888,153. PATENTBD MAY 19, 1908. A. FRANKE.

SYSTEM POR SELECTING CNE OF SEVERAL EECEIVERS CONNECTED TO A'COMMCN CONDUCTOR.

MPLIOATION Hmm 1120.23. 1907.

UNrrED srarns rafrENr oEEroE.

ADOLF FRANKE, OF IIALENSEE, NEAR BERLIN, GERMANY, ASSIGNOR ,lO SIEMENS & HALSKE, A. G., Ol` BERLIN, GERMANY, A CORPORATION OF GERMANY.

sYsTEM EOE SELECTING ONE OF SEVERAL EECEIvEEs CONNECTED To A COMMON CONDUCTOR.

Specification of Letters Patent.

Patented May 19, 1908.

Application led December 23, 1907. Serial No. 407,788.

To all whom it may concern.'

Be it known that I, ADOLF FRANKE, a subject of the German Emperor, and residing at vestfalischestrasse 59, IIalensee, near Berlin, Germany, have invented certain new and useful Improvements in Systems for Selecting One of Several Receivers Connected to a Common Conductor, ot which the following is a specification.

The present invention relates to an electric system for selecting one of several receivers connected to one common conductor. In accordance with the invention this selection is brought about by cach of the electromagnets which are used tor selecting and which ad] oin the individual receivers, switching into circuit a switching mechanism by means of a long continued variation of the electrical state which is produced in the conductor; the switch mechrmism adjoining a receiver is then switched forward by a number of short variations ot current produced in thek conductor in Optional sequence as to time andcorresponding in number to the receiver which is to be selected, and by a subsequent long continued variation ot' current. In this position of the selecting switch the long continued variation of current also causes a signal or the like to be given at the selected station.

The installation can be worked with transmission or with closed-circuit current. In the former case the common conductor leading to the receivers is without current in its normal state, and impulses ol: current ol shorter or longer duration are sent into the conductor when selecting. Willen the installation works with closed-circuit current, the common Conductor of the receivers has a current llowing throughf-the same in its normal state, whereas, when selecting, the short or long continued variations of the electrical state can be brought about either by interrupting the current, by connecting or disconnecting resistance, or by weakening or strengthening the current. Further, the installation can be so arranged that the switchmechanism adjoining each receiver is switched by the variations ol current produced in the line containing the receivers, i. e. the distant line, or the variations of current can inl'luence a local circuit at each receiver by means ol a relay, which local circuit operates the switch-mechanism.

In order that the invention may be clearly understood reference is made to the accompanying drawing in which two embodiments ol the electrical selector system are represented diagrammatically.

In the d1a\\\'ing:-Figure 1 shows the invention used in connection with a system worked with transmission current, whereas Fig. 2 shows a system operated with closedcircuit current to which the invention is applied,

In the installation according to Fig. l the electroinagnets el, e2, e3, a, which each adjoin a receiver and are connected with a switching device are situated in a circuit with the battery l) and key a, the latter heilig open in its normal position. The switching device II, adjoining the recciver-elcctromagnet e, only is represented in the drawing. In its normal position the armature c of the electromagnet c, keeps the contact c, open and is inlluenced by the retarding dcviccf. The switch-disk 7L is on one and the saine axle with the ratchet wheel la, the latter being rotated by the armature ot' the switching electromagnet t'. It the operator at the key c wishes to select, for example, the receiver c, ol which he knows that lor this selection 'live variations of current in the receiver-line are used, by depressing key a he Vlirst causes a long continued llow of current in the receiver-line Z whereby, besides others, the electromagnet cv, is energized. The armature c is slowly attracted until thc contact c, is closed, the resistance which is ollercd by the rctarding device j' device because contact-ring k3 is connected electrically with contact-ring k1. Zhen the key a is now released, the electromagnet i becomes without current, the armature fi, moves away and moves the pawl on it behind the next tooth of the ratchet-wheel Zh. N ow as the receiver .e4 which is to be selected can be brought into the selecting position, i. c. the position in which it can be called, by 'five variations of current, not counting the above mentioned initial long continued flow of current, the key a is first depressed for a short time four times successively and then a long continued variation of current is caused the fifth time. Each impulse or rush of current proceeding from the battery Z) and flowing b ack through the key a, receiver-line Z1, conductor Z3, brush g1, contact-ring k1, contactring k3, brush g3 conductor Z4, ratchet-magnet i, conductor Z2, conductor Zl0 to the battery Z) switches the switching device one step forward, and the fifth rush of current brings the same into the selecting position in which the ring k2 is electrically connected with the brush g4. Under the influence of the fifth long continued closure of the circuit the contact c of the retarding device is again closed, the consequence of which is that a current flows through armature c, contact c1, brush g2, contact-ring k2, brush g4, and the call-bell or alarm w or the like. The alarm w sounds and announces to the concerned operator that he or his receiver is wanted.

The number of the rushes or impulses of current which is necessary for moving the switching device into the selecting position is dependent as is easily seen on the position of the brush g4 relatively to the disk or drum Zt; this position is different in the mentioned selecting switches, so that for bringing about the selecting position of the individual selecting drums, a varying number of rushes of current must be sent through the conductor. The first long continued rush of current which is not counted has no other duty to perform than to release all the selecting switches connected to the conductor, i. c. to make them operative for the short impulses of current which are then sent.

The mode of carrying out the invention which has been described with reference to the drawing is particularly suitable for telegraph installations with Morse operation, in which several Morse apparatus are connected in series in one loop line and can be called from one common sender station. 1n order to be able to select from these as desired one definite Morse apparatus, a selecting switch is arranged at each of them. The selection is then effected in the above described manner. The sounding of the call-bell at the selecting switch causes the concerned operator to set his Morse apparatus for the receipt of the telegram. The Morse signals scales which are then sent through the line by means of the key a are recorded by the Morse apparatus which is connected in circuit, and at the same time switch the selecting switch into the normal position. 1t is self evident that for closing the contact of the retarding device at the selecting switch, a substantially longer impulse of current must be chosen than those necessary for recording the Morse dash, as otherwise the latter could cause the release of a selecting switch. r1`his can be very easily attained by employing a suitable retarding device.

The switching device could be returned into its normal position in another manner also, as, for example, by each of the switchdisks or drums stretching a spiral spring mounted round its axle when it is moved forward. The spiral springs of all the switching mechanisms could be released electromagnetically after the selection is finished, and the switching devices of all the receivers could be thereby returned automatically into their commencing position.

The arrangement represented diagrammatically in Fig. 2 operates with closed-circuit current in contradistinction to the arrangement according to Fig. 1. Here again an electromagnet, ratchet mechanism and switching device are arranged adjoining each receiver. The manner in which the installation is worked is the same as that described with regard to Fig. l. Not one of the switching devices, for example H4, is influenced directly by the variations of current produced in the distant line Zl however, but by means of a local battery b1. 1f, for example, the receiver e4 is to be selected, of which the operator working the switch a knows that it can be selected and that the switching device can be cut out by one long continued interruption.` of current and by means of four short and one subsequent long continued interruption of current in the distant line Z1, the closed-circuit distant line Zl is first opened by depressing the key a until the retarding device f at the receiver has closed the contact c1 of the retarding device. A circuit is thereby made as follows z-local battery b1, conductor Z7, armature c, contact 0 conductor Z8, selecting-contact strip Zcl, brush gl, conductor Z4, electromagnet t, conductor Z2, local battery 5,.

The ratchet-electromagnet fZ therefore attracts its armature il, rotates the ratchetwheel Zt, and with it the drum ZL in the direction of the arrow, so that the brush g, passes onto the circuit contact-ring 7a2. T he switch can now be moved further into the selecting position by four short interruptions of current in the line Z1 and one subsequent long continued interruption. 1n the case of these first interruptions only the contact c2, c3 will be closed by making the receiver e, without current, whereas when the subsequent long continued interruption ot current takes place, on account of which the contact-brush g, comes onto the contact-strip Zr the retarding contact cl is closed and a signal is given by the call-bell or alarm w. The current flows from the battery l), through eenductor Z7, armature c, contact c1, conductor ZS, contact-strip k1, brush gw alarm w and through conductor Z, back to the battery 2),.

In the selecting operation the switching device adjoining the remaining receivers have also been switched forward, but they have not come into their position lor giving a call-signal, as the position ot the brush (i, with regard to the switch-drum 71y is a different one in the case ol all the receivers. This arrangement also is suitable for telegraph installations with Morse operation, and what has been said above in this respect with regard to Fig. 1 holds good here.

It the switching device of the receiver which is to be selected has arrived into the position inA which it gives the signal, a circuit can be closed at the same time by a relay, and after the key a is closed again in the line Zl after the last long continued variations ot the electric state, this closed relay circuit will set the signal in operation until the called subscriber or operator steps up to the apparatus, stops the alarm or the like and, in a given case, sets the writing apparatus lor the reception ot a telegram.

The electrical selecting system can of course be employed everywhere where it is a question of setting into or out olt operation one optional battery, motor, apparatus or the like which is to be selected from a number of batteries, motors, apparatus or the like. The form ol construction can be varied corresponding to the purpose ol' employment in each case. It is only essential in each case that the selection is made by means of receivers in a closed circuit by Iirst a long continued variation ol" current and then a number oli' short variations corresponding to the receiver which is to be selected, a subsequent long continued change of the electrical state being produced in this circuit.

What I claim as my invention and desire to secure by Letters Patent is:

1. In an electrical selecting system of the type described, a plurality of receiver-electromagnets, a source ol current, a switch and a line connecting the same in series, in combination with a second switch adapted to bel operated by one of said receiver-electroniagnets, a retarding device controlling said second switch, a switching device, means for operating the latter controlled by said second switch, and an alarm device connected with and controlled by said switching device, the arrangement being such that the switching device can be switched into the selecting position in which a signal can be sent to the station which is selected under the influence o1 a number ol short variations ol current produced in the line and corresponding to the receiver which is to be selected, and under the influence olE a succeeding long continued variation of the electric state in the line.

2. In an electrical selecting system ol the type described, a plurality of receiver-electromagnets, a source of current, a switch and a line connecting the same in series, in combination with a switching device adjoining one of said receiver-electromagnets and carrying a plurality ol contacts, an electromagnet adapted to drive said switching device; a second switch, a retarding device controlling the latter, an alarm and conductors connecting said second switch, switching device and alarm in a circuit in series with one another and in parallel with one of said receiver-electromagnets; and conductors connecting said switching device and said electromagnet adapted to drive the same in a circuit in series with one another and in parallel with the latter circuit, the arrangement being such that when a long continued rush ol current is sent through the line, the second switch is closed and thereby the current from the line flows through the switching device, and the latter can be switched into the selecting` position under the influence ol" short impulses ot current sent through the line and under the influence ol one subsequent long continued rush of current in the line.

3. In an electrical selecting system of the type described, a plurality ol: receiver-electromagnets, a source ot current, a switch and a line connecting the saine in series, in combination with a second switch adjoining a receiver-electromagnet and a retarding dei vice controlling the latter switch a switching device carrying a circuit-contact and a selecting-contact, ratchet mechanism adapted to operate the switching device and an electromagnet lor operating said ratchet mechanism, an alarm; conductors connecting said circuit-contact and said second switch with one side ol the latter receiver-electromagnet, conductors connecting the other side ot the latter with said alarm and with said ratchetcontrolling elcctromagnet, a conductor nor-4 mally connecting the latter with said selecting-contact and a conductor l'or connecting the alarm with the latter contact when the switching device is driven into the selecting net and inally the alarm when the same is name to this specification in the presence of the line can enei'gize the ratchet-electromagy In testimony whereof I have signed my i i connected with the selecting-Contact, so that two Witnesses.

in this position of the switching device L long` i ADOLF FRANKE. 5 continued rush of current through the line i Vfitnesses:

causes i signal to be given at the concerned t HENRY HASPER,

receiving-station. VVOLDEMAR HAUPT. 

